A pneumatic tire is a polymeric composite and is a complex system of interacting components, each with specific properties for maximum effectiveness. One of the more important components of a tire is the tread. Since the tread of a tire comes into contact with the road, it is particularly compounded for abrasion and tear resistance. For example, abrasion resistance can correlate to tread wear and tear resistance can correlate to the tread""s ability to resist chunking or tearing of the ground contacting tread elements. With the ever present need to improve the performance of tires, there is a continuous need for a rubber composition which improves both abrasion resistance and tear values. One current approach to this problem is the use of silica filler in the tread compounds. Unfortunately, the rubber environment and silica are very dissimilar and there needs to be improved methods to compatibilize this interface to yield better properties.
The present invention relates to a rubber composition particularly suited for the tread of a pneumatic tire. The rubber comprises 100 parts by weight of at least one rubber containing olefinic unsaturation; and from 1 to 150 phr of a silica having dispersed thereon a liquid epoxidized butadiene polymer having a number average molecular weight of from 500 to 10,000.